Specifications

CY8C21123/CY8C21223/CY8C21323
Document Number: 38-12022 Rev. *Y Page 43 of 46
1. Internal Main Oscillator (IMO) Tolerance Deviation at Temperature Extremes
■ Problem Definition
Asynchronous Digital Communications Interfaces may fail framing beyond 0 to 70 °C. This problem does not affect end-product
usage between 0 and 70 °C.
■ Parameters Affected
The IMO frequency tolerance. The worst case deviation when operated below 0 °C and above +70 °C and within the upper
and lower datasheet temperature range is ±5%.
■ Trigger Condition(S)
The asynchronous Rx/Tx clock source IMO frequency tolerance may deviate beyond the data sheet limit of ±2.5% when
operated beyond the temperature range of 0 to +70 °C.
■ Scope of Impact
This problem may affect UART, IrDA, and FSK implementations.
■ Workaround
Implement a quartz crystal stabilized clock source on at least one end of the asynchronous digital communications interface.
■ Fix Status
No silicon fix is planned. The workaround mentioned above should be used.